Fix some typo in documentation

README.md

@@ -17,7 +17,7 @@ The objective of this extension it to propose an extension to provide
 the Global Temporary Table feature waiting for an in core
 implementation. The main interest of this extension is to mimic the
 Oracle behavior with GTT when you can not or don't want to rewrite the
-application code when migrating to PostrgeSQL. In all other case best
+application code when migrating to PostgreSQL. In all other case best
 is to rewrite the code to use standard PostgreSQL temporary tables.
 
 This version of the GTT extension use a regular unlogged table as
@@ -344,7 +344,7 @@ example:
 
 the extension will first create the template unlogged table and will
 create immediately the associated temporary table filled with all data
-returned by the SELECT statement. The firt access will not have to
+returned by the SELECT statement. The first access will not have to
 create the table it already exists with data.
 
 #### Table creation